What is the classification of oxytocin?

Oxytocin is a polypeptide hormone of the posterior lobe of the pituitary gland.

Oxytocin exerts a selective stimulant and rhythmic contraction action on the smooth muscle of the uterus, especially near the end of pregnancy. It increases the frequency of existing contractions and raises the tone of the uterine musculature. Depending on dose, uterine motility may be increased moderately or increased to a sustained tetanic contraction. Oxytocin also has an antidiuretic effect which increases water reabsorption from the glomerular filtrate.

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